Bag pressure indicator for suction cleaners



April 12, 1938. D. C. GERBER 0 BAG PRESSURE INDICATOR FOR SUCTION CLEANERS Filed Oct. 2, 1935 WHEN RID SPOT AFFEARSOPPOSITI ARROW! Patented Apr. 12, 1938 BAG PRESSURE INDICATOR FOR SUCTION CLEANER-S Dale (G. Gerber, NorthCanton, (Ohio, assignor to The Hoover Company, North (Canton, @hio, a

corporation of (lhio Application @ctober 2, 1935, Serial No. 43,141

3 Claims.

This invention relates to improvements in bag pressure indicators for suction cleaners, and more particularly to indicating devices responsive to the pressure within the dust receptacle or bag of a suction cleaner and serving to indicate visually either the condition of the bag or to warn the user that the same, should be emptied of its contents.

The object of the invention is to provide a 3 novel form of indicator adapted to be applied or attached to the bag, and preferably supported directly by the fabric thereof.

The novel features of the bag pressure indicator are clearly shown in the accompanying drawing, in which:

Figure l is a general View in side elevation of a suction cleaner showing the mounting of a pressure indicator adjacent the upper end of the dust bag.

Figure 2 is an enlarged detail view in cross section through the opening provided in the fabric to receive an indicator and showing a plug adapted to be inserted in the absence of such indicator.

Figure 3 is an enlarged plan view of one form 5 of bag mounted pressure indicator as it appears to the operator.

Figure 4 is a cross-sectional view of the indi-" cator, as taken on line l l of Figure 3.

Figure 5 is a view in cross section taken on the 0 line 5-5 of Figure 4.

Figure '6 is a top plan view of a modified form of bag mounted pressure indicator.

Figure 7 is a cross-sectional view of the bag pressure indicator shown in Figure 6 as taken on line 'i'? thereof, and

Figure 8 is a plan view of the bottom or inner side of the indicator shown in Figures 6 and 7.

Without going into detail, the suction cleaner 1 0 herein d sclosed comprises a wheeled casing 5 having a nozzle 2 opening downwardlyin close proximity to the floor and communicating with a. fan chamber in which is. located a fan 3 driven by a motor enclosed within its casing 4%. Lead- 5 ing from the fan chamber is an exhaust duct or passa e terminating in an annular outlet confraction 5 to which is attached one end of a fabric dust collecting bag '6, the same being supported at its upper end by a suitable flexible connector 3 I to a handle 8 pivotally connected to the main casing I of the cleaner by means of a ball 9.

As well known in the art the cleaner is maneuvered over the floor and the dirt extracted from the floor covering by the suction created at the nozzle by the fan, is discharged through the exhaust passage and into the bag 6. The fabric of the bag is permeable in a degree to the air entering the same under pressure, so that while it is inflated during the operation of the cleaner, sufficient air escapes through the fabric to avoid it the creation of any considerable back pressure, a condition that exsists so long as the bag remains relatively clean. However, after the cleaner has been in operation for a considerable period of time, the dirt accumulating in the bag lib reduces the permeability of the fabric, and causing a back pressure that is evidenced by a material decrease in the eificiency of the cleaner.

Thus as a means of indicating the" condition within the bag and particularly, to warn the operator that the bag is dirty and requires cleaning, the. indicator it is located adjacent the upper end of the bag as clearly shown in Figure 1. By preference an opening is provided at the point where the indicator is located, this opening being formed in the fabric of the bag and reinforced by a metal ring ii, although a rubber plug i2 may be' fitted into the opening, as shown in Figure 2, in the event the indicator is to be omitted or until such time as one is to be installed.

Referring now to Figures 3, i and 5, the indicating device it comprises parts as follows: An annular plate it having a slightly rounded or convex'exterior surface forms a body member or support for the moving parts of the indicator including a bellows type of pressure responsive element M consisting of a cup-shaped member of flexible material with corrugated annular side walls and a flat bottom wall. This bellows member is secured centrally of the body member by means of an L-shaped collar iii having a radiai flange seating in a recess i3a in the inner face of the body member and clamping therebetween the outwardly turned margins of the bellows. w The collar [15 is suitably fastened or anchored to the body member it with its radially flanged portion substantially flush with the inside face thereof, said collar having an angular flange projecting beyond said inside face for insertion through 5 the ring ii reinforcing the opening in the fabric of the bag. The flanged portion of the collar l5, projecting through the opening in the bag, is threaded to receive a lock ring i 6 which is screwed thereon from the inside of the bag to hold the 5 indicator securely in place.

At the center of the outer face of the plate I3 is a slightly rounded circular projection bisected by a vertical slot I1 and adapted to move lengthwise of this slot an arm 18 journalled on two body forming members.

a pin i 9 extendingtransversely between two ears 2t, 2t formed integrally with the plate l3 and projecting at right angles from its inner face on both sides of the slot i'i. At its pivoted end, the arm it has a short lever arm Illa. arranged at right angles thereto, with its end connected at the center of the end wall of the bellows M by means of a short link it and a pin 22 anchored in said end wall, the latter, as clearly shown in Figure 4, being preferably reenforced on opposite sides by circular reenforcing plates idai4a.. And finally, a light spring 23 is coiled around the pivot pin it of the am it with a U-shaped portion 23a straddling the arm it, as is clearly shown in Figures 4 and 5, and its ends abutting a cross pin it extending between the ears it, thus normally holding the arm at the lower end of the slot ll. The tip end of the signal arm H8 is preferably colored in red or some other readily visible color, so that its position in the slot [ill can be easily seen by the operator. Under normal operating conditions, that is say, when the bag is clean, the indicator arm i8 is held at the lower end of the slot, which position is designated by the word Clean. As long as the pressure within the bag does not exceed a predetermined maximum the signal will not change position, but when the pressure, due to the excessive accumulation of dirt in the bag, becomes great enough to overcome the combined resiliency of the bellows M and the tension of the spring 23, the bellows will contract thus actuating the indicator arm it causing the signal to move toward the opposite end of the slot ill designated by the word Dirty. Manifestly, the

movement of the signal is an indication of excessive dirt in the bag and registers its warning when the cleaner is in operation and until the bag has been emptied, whereupon the signal arm will return to the "clean position and so remain until the bag again requires cleaning.

Figures 6, 7 and 8 show a modified construction for a bag pressure indicator somewhat similar to that ,just described, but embodying, a difierent form of signal. The body of the indicator comprises a two-part casing, made up of a circular plate-like member 25 and a tubular member 26, having an annular flange portion 26a concentric with said platemember. As clearly shown in Figure '7, the inner contacting marginal faces of the two sections 25 and 26 are provided with interfitting annular shoulders and recesses between which is clamped the'fabric around an opening formed in the bag and the whole fastened together by rivets 27. The tubular member it of the casing is located on the inside of the bag and is preferably disposed at an angle of substantially 30 degrees to the plane of parting of the Extending axially of the angularly arranged tubular portion is an integral bearing is having an axial bore supporting a rod 29 constituting the signal member. Closing the inner end of the tubular member 25 is a bellows member 30, identical in every respect to the bellows member it shown in Figure 4. This bellows member is suitably fastened over the end of the tubular portion, thus forming a cavity or chamber sealed from the interior of the bag 6. The rod or signal member 28 is attached at its inner or lower end to the center of the end wall of the bellows member 30 and surrounding the rod between said end wall and the adjacent end of the bearing 28 is a coil spring 3! acting to hold the bellows member in extended position and to oppose its contraction" under the pressure of the air in the bag and the accompanying endwise movement of the signal member 29. The outer free end of the signal member or rod 29 is supported by a separate bearing 25a. integral with the member 25 and projecting obliquely from its inner face in alinement with the main bearing 28 supportingthe signal rod 29.

And finally, as shown in Figure 7, the outer end portion 29a of the rod is tipped in some readily distinguishable color such as red, but under normal conditions of operation the rod is retracted into the outer bearing 25a to such an extent that the tip end thereof is not visible to the operator. I

However, when the bag becomes dirty and the pressure increases therein, it follows that the bellows member 30 will be contracted, thus shifting the signal rod endwlse and in an upward direction, whereupon the tip thereof appears in the somewhat enlarged entrance to the bearing 2541 as a red spot between the arrows marked on the outer face of the plate, as clearly shown in Figure 6, the appearance of this red spot manifestly indicating that the bag should be emptied.

In construction, function and purpose both types of pressure indicators are quite similar, being sufiiciently light and compact to be readily incorporated in the bag and supported by the fabric. This permits the positioning of the indicator considerably nearer the operator than is otherwise possible and at a point where the signal is more likely to be observed. Therefore, except for the fact that one type of indicator is arranged to register the existing condition in the bag as clean or dirty and the other type to display a visual warning signal when the bag is to be emptied, both are equally satisfactory and useful adjuncts to a suctioncleaner.

Having set forth a preferred embodiment of my invention, I claim:

1. In a pressure indicator for the purpose described, the combination with a container of flexible material having an opening formed in the wall' thereof, of a relatively flat body member fastened to the exterior surface of said container with its central portion registering with the opening therein, a bellows member fastened to said body member and subject to the pressure changes in said container, and a signal member oper atively connected with said bellows member and having its end portion tipped with a contrasting color, said body member having a slot therethrough in which the end of said signal member is visible to indicate pressure changes in said container.

2. In an air pressure indicator for the purpose described, the combination with a container of.

flexible material having an aperture formed at a predetermined point in the wall thereof, of a relatively fiat body member inserted into said aperture in the wall of said container and clamped about the margin thereof", said body member having a cavity in the rear face and a slot extending through to the front face thereof, a pressure responsive element mounted on the rear face of said body member and enclosing said cavity, and a signal member carried by said member and operatively connected with said pressure responsive element and having a visible portion shiftable in said slot to indicate pressure body member adapted to be clamped about its margin to the material of said container about said aperture, and having a recessed central portion provided with a slot visible on the outer face thereof, a bellows member closing ofl said recessed portion and exposed to the pressure within said container, and a signal member on said body member and operatively connected with said bellows member and comprising an arm adapted to swing lengthwise in said slot to visually indicate variations in air pressure in said container.

DALE C. GERBER. 

